hello anatomy colleagues let's talk the joints of the ankle region
so we're going to spend obviously the majority of our time when we're talking about the ankle
region talking about the ankle joint but I do want to touch base regarding some of those tibiofibular
joints it's similar to what we had between the radius and the ulna with three separate joints
so there are going to be the three separate joints it'll be a proximal tibiofibular
joint, there'll be a distal tibiofibular joint, and then there'll be the interosseous membrane between
this proximal tibiofibular joint is a synovial joint specifically
a plane joint there's very slight sliding movement gliding movements occurring there
the interosseous membrane as well as the distal tibiofibular joints are syndesmosis so these are
examples of fibrous joints they will allow a little bit of movement to occur there
certainly not to the level of what we had between the radius and the ulna i do wanted I did
excuse me I'm losing my voice a bit I did want to mention that the interosseous membrane in this
region as well as between the radius and the ulna is going to be an important muscle attachment site
so I brought this up mainly because I did want to point out that we do have
that similar setup in the leg as we had in the forearm also because particularly the
distal portions of the interosseus membrane and the distal tibiofibular joint can be damaged
sometimes in unison with the ankle region and sometimes you will hear this referred to
as a high ankle sprain if you have damage to some of those structures
okay let's talk about the talocrural but more often we refer to this as the ankle
joint so recall that you're going to have these distal portions of the tibia and the
fibula playing a role particularly the distal part of the tibia here will articulate with the
talus or the talus and then we have of course the lateral malleolus and the medial malleolus
on either side of the ankle joint allowing for this kind of full complex between these bones
this is an example of a synovial hinge joint so you'll have flexion and extension occurring here
but in this particular region we refer to this as dorsiflexion and plantarflexion so with
dorsiflexion you're going to have the dorsum of the foot being flexed
so the dorsum is this kind of top part if you were to look down at your foot you'd be looking at the
dorsum of your foot then of course you have the plantar surface of your foot as well so that's
where the you have the dorsal part flexing in this particular way so I think the toes are pointing
up in the air whereas with plantarflexion you're going to have your toes pointing down
think of a individual doing ballet they're standing on their toes they are plantarflexing
you have some very powerful ligaments in this region as well because you don't have a lot of
muscle ten- or you do have muscle tendons that that's not true you certainly have
muscle tendons associated with this region and they do play a role in terms of protection but
ligaments are playing a bit of a stronger role in this particular joint and they vary significantly
rather whether you're talking about the medial ligaments or the lateral ligaments so the
deltoid or the medial ligaments are going to be strong they are going to play a big role in terms
of protection of the medial side of not only the ankle joint but some of the surrounding joints
in this region all of these medial or deltoid ligaments are going to kind of interweave together
and attach to the medial malleolus or malleolus okay so they interweave together forming this block
basically that's protecting that medial side so it's protecting the medial side of the talocrural
joint but it also will stabilize the ankle during eversion and we'll talk a little bit more
about that in a moment but you will see that you are capable of doing quite a bit more inversion
than eversion and that has a lot to do with the the strength of these medial or deltoid ligaments
all right now if you look at the other side if you look at the lateral side of the ankle joint
you have ligaments here as well in fact you have three separate ligaments they all attach on the
lateral malleolus but they don't interweave like what you had here on the medial side
so they are not nearly as robust not nearly as strong and they do not confer the same amount of
stability as you had on the medial side in fact the anterior talofibular ligament is one of the
most commonly torn ligaments in the body and these ligaments not only protect the lateral side of the
ankle joint but they will stabilize the ankle during inversion so what is this eversion and
inversion that I keep talking about well first off these don't occur this type of movement does
not occur directly at the ankle joint remember the ankle joint is a true hinge joint but eversion
and inversion often occur at the same time as movement of the ankle joint so this will occur
specifically at the subtalar joint which is between the talus and the calcaneus as well
as with this transverse tarsal joint between the talus calcaneal region and the other tarsal bones
and so what inversion and eversion is is inversion you can think of the sole of the foot
kind of turning more medially whereas with eversion the sole of the foot or
the plantar surface of the foot so this would be the plantar surface is going to move more
laterally and if you invert or evert your own foot you will see that you have quite a bit
more of a range of motion with inversion than you do with eversion so recall that those medial
ligaments are really preventing over-eversion whereas the lateral ligaments are supposed to
be preventing over-inversion but those lateral ligaments recall are not quite as strong as what
you had and so this most ankle sprains are going to be due to an over-inversion injury
that's by far the most common cause of an ankle sprain so if you think if you're stepping down say
from off the street or something like that you land funny often your your ankle will move kind of
oddly and then you will over-invert and that can cause injury to these lateral ligaments
so these are by far the more commonly damaged ligaments of the whole body but certainly in terms
of the ankle region really the ankle is one of the most frequently injured major joints of the body
all right excellent so this one is a real simple question
something I hope that we we've gotten down if not we certainly need to make sure we review so the
talocrural joint is capable of plantar- as well as dorsiflexion what type of synovial joint is it
so pause the video if you need time and when you're ready i hope you have landed on c
hinge joint so we have flexion and extension is capable at the talocrural or ankle joint
but in this particular joint we refer to it specifically as plantar- or dorsiflexion
so it's only this movement in this one plane that we have occurring at the talocrural joint
certainly not a ball & socket, condyloid, plane that would not be enough movement and then saddle is
not correct either all right excellent so those are the major joints of the lower limb that we
are going to discuss the rest of our time we're going to be talking about the muscles
associated with the lower limb what they do what they're innervated by
and then we will be finished thank you so much for your time and i will see you in the next video